Malicious RTF — malware analysis report

Static analysis result for SHA-256 d613285ecc373bd6…

MALICIOUS

RTF

13.5 KB First seen: 2023-03-17
MD5: 984eb11b3f5de9345be40b9fdf432400 SHA-1: dcdb7a00279a40aec32c7cb48d83b110155ceb22 SHA-256: d613285ecc373bd6fcc8453ef8e877adba090dbe1a2a585bee5d15865c7ecd62
160 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File Execution: User Execution: Malicious File

The RTF document contains OLE objects and specifically triggers heuristics related to Equation Editor exploitation (RTF_EQUATION_EDITOR, RTF_OBJAUTLINK, RTF_OBJUPDATE). This indicates the file is designed to leverage a known vulnerability to execute arbitrary code, likely to download and run a subsequent stage. The malformed document body and lack of clear user-facing content further support a malicious intent rather than legitimate document exchange.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000013ab.bin
278e77fc7d9571941a743975e2c9b8bfad17b826fba8d5e6c77f9c28e010831c
rtf-objdata-decoded RTF \objdata at offset 0x13AB 1891 bytes